1)
Why did he say "Im Elech b'Kerev Tzarah"?
1.
Radak: David says, when I was going amidst Tzarah, and I was close to death, You revived me.
2.
Malbim: Your Hashgachah over me is so found and close, that even when I am amidst Tzarah, You sustain me.
2)
What is the meaning of "Al Af Oyvai"?
1.
Radak: On my enemies' anger, i.e. Bal Korcham (against their will), not for their benefit.
3)
Where does Hashem send His hands?
1.
Radak: Amidst the affliction.
2.
Malbim: Against the anger of my enemies.
4)
Why does it mention "Yadecha" and "Yeminecha"?
1.
Malbim: Din (the left hand) and mercy (the right hand) act together.